The heavy artillery and organisation employed by the Germans, along with gruesome scenes of body parts strewn across the battlefield, had a shocking effect on the Australian troops, who were almost entirely civilian volunteers with limited military training.

The famous phrase "Don't forget me, cobber" originated in Fromelles, when it was shouted by a wounded soldier at Sergeant Simon Fraser — who reported on the aftermath in a letter home — during a rescue mission.

It has also been established that 27-year-old Corporal Adolf Hitler was amongst the Germans in Fromelles fighting the Australians.

Although the six-week battle for Pozieres was somewhat a success, with allied forces taking over the town, there were some 23,000 Anzac casualties, a figure comparable to the 28,000 suffered during the eight months spent fighting in Gallipoli.

Australian WWI correspondent Charles Bean famously reported the Pozieres ridge was "more densely sown with Australian sacrifice than any other place on Earth".

"The men were simply turned in there as into some ghastly giant mincing machine," he later wrote.

The Australian War Memorial — which was conceived by Bean during the 1916 battles — says that "for men thrown into the fighting at Pozieres, the experience was simply hell".

"My tunic is rotten with other men's blood, and partly splattered with a comrade's brains. It is horrible, but why should you people at home not know?" Lieutenant John Raws later wrote.

"Several of my friends are raving mad. I met three officers out in No Man's Land the other night, all rambling and mad."

The two battles served as a cruel introduction to the harshness of the war on the Western Front, and as word of the gruesome battles got out volunteer numbers began to fall.

Until that point, only military service was mandatory for Australians.

Hughes had long wanted to introduce conscription, rather than voluntary recruitment, but could not get the support in the Government, so on October 28, 1916, Australians were asked:

"Are you in favour of the Government having, in this grave emergency, the same compulsory powers over citizens in regard to requiring their military service, for the term of this War, outside the Commonwealth, as it now has in regard to military service within the Commonwealth?"

The referendum was narrowly defeated — 51 per cent against versus 49 per cent for — with many attributing reports of the Battles of Fromelles and Pozieres as the reason.

But Australians remained bitterly divided over the issue.

"There were lots of reasons why Australians voted no, ranging from labour unions fearing conscription would hand jobs over to immigrants, to libertarians outright saying it's not right to force a man to kill," Professor Beaumont says.

"But the meetings and debates became quite violent. Everyone knew who had served and who hadn't in their communities, and people would get on tables and name names.

"It is by far one of the fiercest debates in Australia's history."

One of the consequences of the debates that lingers in Australia today, Professor Beaumont says, "is the entrenched belief that you could not conscript men to fight overseas" — an issue that was touched upon again in subsequent wars.

Nonetheless, 1916 — through the Battles of Fromelles and Pozieres — is widely seen as the first year Australians played a full role in WWI, and although many of that year's offensives did not achieve their goals, they helped deal significant blows to German forces.